화학공학소재연구정보센터
Fluid Phase Equilibria, Vol.280, No.1-2, 35-41, 2009
Solubility and limiting activity coefficient of simvastatin in different organic solvents
Equilibrium mole fraction solubility of Zocor (R) (simvastatin) a pharmaceutically important compound, was measured between 279 and 315 K, in fifteen different industrial-relevant organic solvents including: methyl acetate, ethyl acetate, propyl acetate, iso-propyl acetate, butyl acetate, iso-butyl acetate, sec-butyl acetate, tert-butyl acetate, and ethanol, propanol, 1-butanol, 2-butanol, 1-pentanol, 1-hexanol, and 1 octanol. Fusion enthalpy, Delta H-fus, melting point temperature, T-m, were measured to be 32,169 J/mol, 412.6 K, respectively: and the difference in the molar heat capacity (at constant pressure) of the liquid, and solid form of simvastatin, Delta C-P, was approximated (by extrapolation) to be 230J/mol K. Dissolution of simvastatin was found to be endothermic, and entropically favorable. The activity coefficient at infinite dilution of simvastatin in each solvent was calculated from the experimental data, then fitted to Gibbs-Helmholtz equation to estimate the limiting partial molar excess enthalpies, (H) over bar (E,infinity), and the limiting partial molar excess entropies, (S) over bar (E,infinity). The data was also fitted to the non-ranclorn-two-liquid (NRTL) activity coefficient equation to generate the model interaction parameters for dissolution of simvastatin in the organic solvents studied here. (C) 2009 Elsevier B.V. All rights reserved.